ISO 7547:2022

INTERNATIONAL ISO
STANDARD 7547
Third edition
2022-04
Ships and marine technology —
Air-conditioning and ventilation of
accommodation spaces and other
enclosed compartments on board
ships — Design conditions and basis
of calculations
Navires et technologie maritime — Conditionnement d'air et
ventilation des emménagements et autres compartiments fermés à
bord des navires — Conditions de conception et bases de calcul
Reference number
ISO 7547:2022(E)
© ISO 2022

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ISO 7547:2022(E)
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© ISO 2022
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Published in Switzerland
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ISO 7547:2022(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Design conditions . 2
4.1 General . 2
4.2 Summer temperatures and humidity . 2
4.3 Winter temperatures . 2
4.4 Outdoor air . 3
4.5 Occupancy . . 3
5 Calculation of heat gains and losses . 3
5.1 Applicability . 3
5.2 Heat transmission . 4
5.2.1 Method of calculation . 4
5.2.2 Temperature differences between adjoining internal spaces . 5
5.2.3 Total heat transfer coefficients . 5
5.2.4 Calculation of the heat transfer coefficient . 5
5.2.5 Measurement of transmission areas . 7
5.3 Solar heat gain. 7
5.4 Heat gain from persons . . 8
5.5 Heat gain from lighting and other sources . 8
6 Airflow calculation . 9
6.1 Volume of space. 9
6.2 Supply airflow . 9
6.2.1 Air supply for air-conditioning . 9
6.2.2 Air supply for ventilation . 9
6.3 Temperature of supply airflow . 10
6.4 Exhaust airflow . 10
6.4.1 Volume of airflow . 10
6.4.2 Exhaust system . 10
6.5 Air balance . 10
Annex A (informative) Guidance and good practice in the design of ventilation and air-
conditioning systems in ships . .11
Annex B (informative) Thermal conductivities of commonly used construction materials .14
Annex C (normative) Additional requirements for machinery control-rooms .15
Annex D (normative) Additional requirements for the wheelhouse .17
Annex E (normative) Additional requirements for dry provision store rooms .19
Annex F (normative) Additional requirements for hot-air heating of wheelhouse windows .21
Bibliography .22
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ISO 7547:2022(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
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expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 8, Ships and marine technology,
Subcommittee SC 3, Piping and machinery.
This third edition cancels and replaces the second edition (ISO 7547: 2002), as well as ISO 8862:1987,
ISO 8863:1987, ISO 8864:1987 and ISO 9099:1987, which have been technically revised. It also
incorporates the Technical Corrigendum ISO 7547:2002/Cor.1:2008.
The main changes are as follows:
— incorporation of smaller ship ventilation standards (ISO 8862, ISO 8863, ISO 8864, ISO 9099) into
this document;
— minor editorial changes made in conformity with the ISO/IEC Directives, Part 2, 2021.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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INTERNATIONAL STANDARD ISO 7547:2022(E)
Ships and marine technology — Air-conditioning and
ventilation of accommodation spaces and other enclosed
compartments on board ships — Design conditions and
basis of calculations
1 Scope
This document specifies design conditions and methods of calculation for air-conditioning and
ventilation of accommodation spaces on board seagoing merchant ships for all conditions, except those
encountered in extremely cold or hot climates (i.e. with lower or higher conditions than those stated
in 4.2 and 4.3). This document also provides special considerations for machinery control-rooms,
wheelhouse, and dry provision store rooms in Annexes C, D and E.
NOTE Statutory requirements, rules and regulations can be applicable to the individual ships concerned.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 80000-5, Quantities and units — Part 5: Thermodynamics
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 80000-5 and the following
apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
accommodation
space used as public rooms, cabins, offices, hospitals, cinemas, games and hobby rooms, hairdressing
salons and pantries without cooking appliances
3.2
machinery control-room
space containing the system of the main alarm displays and the controls for the propulsion machinery
3.3
wheelhouse
enclosed area of the bridge, excluding radio cabin
3.4
air-conditioning
form of air treatment whereby temperature, humidity, ventilation (3.5) and air cleanliness are all
controlled within limits prescribed for the enclosure to be air-conditioned
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ISO 7547:2022(E)
3.5
ventilation
provision of air to an enclosed space, sufficient for the needs of the occupants or the process
3.6
relative humidity
ratio, in humid air, expressed as a percentage, of the water vapour actual pressure to the saturated
vapour pressure at the same dry bulb temperature (3.7)
3.7
dry bulb temperature
temperature indicated by a dry temperature-sensing element shielded from the effects of radiation
EXAMPLE The bulb of a mercury-in-glass thermometer is an example of a dry temperature-sensing element.
3.8
dry provision store room
enclosed compartment, provided with lighting and ventilation (3.5), for storage of provisions for the
ship’s crew
4 Design conditions
4.1 General
The air-conditioning and ventilation system shall be designed for the indoor air conditions specified
in 4.2 and 4.3 in all accommodation spaces defined in 3.1 at the stated outdoor air conditions and the
outdoor supply airflow, ventilation and air balance given in 6.2.1, 6.2.2 and 6.5 respectively.
Machinery control rooms, the wheelhouse, and dry provision store rooms shall meet the additional
ventilation and air conditioning requirements of Annexes C, D and E, respectively.
Hot air heating systems for ship wheelhouse windows shall meet the additional requirements of
Annex F.
NOTE All temperatures stated are dry bulb temperatures.
4.2 Summer temperatures and humidity
Summer temperatures and humidity are as follows:
a) outdoor air: +35 °C and 70 % relative humidity;
b) indoor air: +25 °C and 55 % relative humidity;
c) engine room air: +45 °C.
NOTE In practice, the indoor air conditions obtained, especially humidity, can be different from those stated.
4.3 Winter temperatures
Winter temperatures are as follows:
a) outdoor air: −20 °C;
b) indoor air: +22 °C.
NOTE This document does not specify requirements for humidification in winter. In practice, the indoor air
conditions obtained can be different from those stated.
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ISO 7547:2022(E)
4.4 Outdoor air
3
The minimum quantity of outdoor air in the total air supplied shall be not less than 0,008 m /s per
person, based on the occupancy numbers for accommodation spaces provided in 4.5.
NOTE See also 6.2.1 c) for outdoor air requirements based on the personnel occupancy design of the space.
4.5 Occupancy
The number of persons allowed in the various accommodation spaces shall be as follows, unless
otherwise stated by the purchaser.
a) Cabins:
— the maximum number of persons for which the cabin was designed.
b) Public rooms, such as saloons, mess- or dining-rooms and recreation rooms:
— the number of persons who can be seated or, in the case where the purchaser does not specify
it:
2
i. one person per 2 m floor area for saloons;
2
ii. one person per 1,5 m floor area for mess- or dining-rooms;
2
iii. one person per 5 m floor area for recreation-rooms.
c) Captain’s and chief engineer’s day-room:
— four persons.
d) Other private day-rooms:
— three persons.
e) Hospital:
— the number of beds plus two.
f) Gymnasium, games-room:
— four persons.
NOTE The number of persons in gymnasiums can vary based on the ship size and design.
g) First-aid-room:
— two persons.
h) Offices:
— two persons.
i) Machinery control-room:
— three persons.
5 Calculation of heat gains and losses
5.1 Applicability
For the calculation of summer conditions, 5.2 to 5.5 inclusive shall apply. For the calculation of winter
conditions, only 5.2 shall apply.
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ISO 7547:2022(E)
5.2 Heat transmission
5.2.1 Method of calculation
Formula (1) shall be used for calculating the transmission losses or gains, in watts, for each separate
surface:
Φ =ΔTk Ak+ A  (1)
() ()
vv gg
 
where
∆T is the difference in air temperature, in kelvins, (for the difference of air temperature between
air-conditioned and non-air-conditioned internal spaces, see 5.2.2);
k is the total heat transfer coefficient, in watts per square metre kelvin, for the surface area A
v v
(see 5.2.3);
A is the surface area, in square metres, excluding side scuttles and rectangular windows (glaz-
v
ing +200 mm) (see Figures 1 and 2);
k is the total heat transfer coefficient, in watts per square metre kelvin, for the surface area A
g g
(see 5.2.3);
A is the surface area, in square metres, of side scuttles and rectangular windows (glazing
g
+200 mm) (see Figures 1 and 2).

Dimensions in millimetres
Figure 1 — Side scuttles
Dimensions in millimetres
Figure 2 — Rectangular windows
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ISO 7547:2022(E)
5.2.2 Temperature differences between adjoining internal spaces
For differences of air temperature, ∆T, in kelvins, between conditioned and non-air-conditioned internal
spaces, see Table 1.
Table 1 — Temperature differences between adjoining internal spaces
∆T, K
No. Deck or bulkhead
Summer Winter
1 Deck against tank provided with heating 43
2 Deck and bulkhead against boiler-room 28
17
Deck and bulkhead against engine-room and against non-air-
3 18
conditioned gallery
Deck and bulkhead against non-heated tanks, cargo spaces and
4 13 17
equivalent
5 Deck and bulkhead against laundry 11 17
6 Deck and bulkhead against public sanitary space 6 0
a) with any part against exposed external surface 2 0
Deck and bulkhead
7 against private b) not exposed 1 0
sanitary space
c) with any part against engine/boiler-room 6 0
Bulkhead against alleyways, store rooms, equipment rooms, or eleva-
8 2 5
tor trunks
NOTE It is understood that means of heating are provided in exposed sanitary spaces.
5.2.3 Total heat transfer coefficients
The values for the total heat transfer coefficients, k, in watts per square metre per kelvin, given
in Table 2, assume that adequate thermal insulation is provided on all surfaces exposed to outdoor
conditions or adjoining hot or cold spaces, or hot equipment or pipework.
The values given in Table 2 shall be used where appropriate, unless otherwise advised by the purchaser.
For other cases, a method for the calculation of the heat transfer coefficient is given in 5.2.4.
5.2.4 Calculation of the heat transfer coefficient
The heat transfer coefficient shall be calculated according to Formula (2):
d
∑+MM+
Lb
11
λ
=∑ + (2)
k α μ
where
2
k is the total heat transfer coefficient, in watts per square metre kelvin [W/(m ·K)];
α is the coefficient of heat transfer for surface air, in watts per square metre kelvin
2
[W/(m ·K)], as follows:
2
 α = 80 W/(m ·K) for outer surface exposed to wind (20 m/s),
2
 α = 8 W/(m ·K) for inside surface not exposed to wind (0,5 m/s);
d is the thickness of material, in metres;
λ is the thermal conductivity, in watts per metre kelvin [W/(m·K)];
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ISO 7547:2022(E)
2
M is the thermal insulance for an air gap, in square metres kelvin per watt [(m ·K) /W];
L
M is the thermal insulance between different layers of material, in square metres kelvin per watt
b
2
[(m ·K) /W];
µ is a correction factor for steel structure as follows:
 µ = 1,2 for insulation in accordance with Figure 3,
 µ = 1,45 for insulation in accordance with Figure 4.

Key
a air gap thickness
Figure 3 — Plane insulation of uniform thickness
Key
a air gap thickness
Figure 4 — Corrugated insulation of uniform thickness
Table 2 — Total heat transfer coefficient
Total heat transfer coefficient
No. Surfaces
2
W/(m ·K)
Weather deck not exposed to sun’s radiation and ship side
1 0,9
and external bulkheads
Deck and bulkhead against engine-room, cargo space or
2 0,8
other non-air-conditioned spaces
Deck and bulkhead against boiler-room or boiler in
3 0,7
engine-room
Deck against open air or weather deck exposed to sun’s
4 0,6
radiation and deck against hot tanks
5 Side scuttles and rectangular windows, single glazing 6,5
6 Side scuttles and rectangular windows, double glazing 3,5
7 Bulkhead against alleyway, non-sound reducing 2,5
8 Bulkhead against alleyway, sound reducing 0,9
9 Control-room bulkhead and ceiling against engine room 0,8
10 Control-room floor against engine room 1,2
11 Window, triple glazing 2,5
NOTE Guidance on values of thermal conductivities of commonly used materials is given in Table B.1.
For the thermal insulance, M , of non-ventilated air gaps, see Table 3.
L
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ISO 7547:2022(E)
Table 3 — Thermal insulance of non-ventilated air gap
a b
Air gap thickness, a Thermal insulance
Boundary surfaces of air gap
2
mm m ·K /W
5 0,11
Both surfaces having high emissivity 20 0,15
200 0,16
5 0,17
One surface having high emissivity,
20 0,43
other surface low emissivity
200 0,47
5 0,18
Both surfaces having low emissivity 20 0,47
200 0,51
c
High emissivity surfaces in contact 0 0,9
a
See Figures 3 and 4.
b
The term “thermal insulance” is used according to the definition given in ISO 80000-5. In many countries, this term is
known as “thermal resistance” with a symbol R.
c
Aluminium foil and other polished surfaces are assumed to have low emissivity (0,2). All other surfaces are assumed to
have high emissivity (0,9).
5.2.5 Measurement of transmission areas
The transmission areas for bulkheads, decks and ship sides shall be measured from steel to steel.
5.3 Solar heat gain
The solar heat gain, Φ , is calculated, in watts, according to Formula (3):
s
Φ =∑AkΔTA+∑ G (3)
s vr gs
where
A is the surface area exposed to solar radiation in square metres (side scuttles and rectangular
v
windows are not included);
k is the total heat transfer coefficient in accordance with 5.2.3 or 5.2.4 for a ship structure (deck,
outer bulkhead) within the surface A ;
v
∆T is the excess temperature (above the outside temperature of +35 °C) caused by solar radiation
r
on surfaces as follows:
 ∆T = 12 °C for vertical light surfaces,
r
 ∆T = 29 °C for vertical dark surfaces,
r
 ∆T = 16 °C for horizontal light surfaces,
r
 ∆T = 32 °C for horizontal dark surfaces;
r
A is the glass surfaces (clear opening) exposed to solar radiation, in square metres;
g
G is the heat gain per square metre from glass surfaces as follows:
s
2
 G = 350 W/m for clear glass surfaces,
s
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ISO 7547:2022(E)
2
 G = 240 W/m for clear glass surfaces with interior shading.
s
For corner cabins, the surface which gives the highest Φ shall be chosen for the calculation of the heat
s
gain.
Surfaces not included in A , because of shadow from overhanging deck or other means of sun protection,
v
shall be calculated at a sun angle of 45°.
NOTE 1 If solar radiation reflecting glass is used, G can be reduced.
s
NOTE 2 The excess temperatures for vertical and horizontal surfaces and the additional heat gain from glass
surfaces caused by solar radiation are based on the most extreme average temperatures in subtropical climate
and give the “worst condition” occurring during a day.
5.4 Heat gain from persons
Values of sensible and latent heat emitted by a person at an indoor temperature of 27 °C are given in
Table 4.
Table 4 — Body activity and heat emission
Emission
Activity Type of heat
W
Sensible heat 70 120

Seated at rest

Latent heat
50 (total heat)

Sensible heat 85 235

Light work

Latent heat 150 (total heat)

The total heat values in Table 4 are generally the same at 24 °C. Heat values for females should be 85 %
of listed values. Heat emission increases proportionally based on the increasing level of activity and
work level.
5.5 Heat gain from lighting and other sources
In spaces with daylight, additional heat gain from lighting shall be ignored. In spaces without daylight,
the heat gain from lighting shall be calculated from the rated wattage of the lighting, as advised by the
purchaser or as specified by the appropriate authority. Where the rated output is not specified by the
purchaser or the appropriate authority, the heat gain from general lighting shall be taken as stated in
Table 5, with consideration given to special lighting requirements.
Table 5 — Heat gain from general lighting
Heat gain from general lighting
2
Space
W/m
Incandescent Fluorescent LED
Cabins 15 8 4
Mess- or dining-rooms 20 10 5
Gymnasiums 40 20 10
Refrigerator output shall be taken as 0,3 W/l storage capacity, unless otherwise specified by the
purchaser.
Other sources of heat gain, such as from appliances that are in operation for considerable periods during
the day, shall only be taken into consideration if specified by the purchaser.
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ISO 7547:2022(E)
Temporary electrical appliances, such as radio and television sets, and hot water urns, shall be ignored.
The heat gain from equipment in the radio cabin shall be taken as 2,5 kW, unless otherwise specified by
the purchaser.
Heat gain from fans shall be taken to give a rise in the temperature of the air of 1 °C/kPa total pressure
rise.
The rise in the temperature of the air in ducts shall be limited to +1,5 °C in supply air ducts and +2 °C in
return air ducts.
6 Airflow calculation
6.1 Volume of space
The volume of furniture, wardrobes, and similar stationary equipment shall not be deducted in
calculating the gross volume of cabins and other spaces.
6.2 Supply airflow
6.2.1 Air supply for air-conditioning
The air supply to each air-conditioned space shall be calculated using whichever of the following criteria
gives the highest value:
a) airflow to maintain the conditions of 4.2;
b) airflow to maintain the conditions of 4.3;
3
c) outdoor supply airflow not less than 0,008 m /s per person for which the space is designed.
Private sanitary rooms (bath, shower or W.C.) ventilation shall be based on 10 air changes per hour-see
6.4.1.
NOTE 1 National regulations can specify a minimum number of air changes.
3
NOTE 2 For crowded areas, such as mess rooms and changing rooms, 6.2.1 c) can be adjusted to 0,007 m /s
per person.
NOTE 3 See Annex A (A.11), for additional technical guidance regarding calculation of heating, ventilation and
air conditioning (HVAC) airflow rates.
6.2.2 Air supply for ventilation
Supply of conditioned air to ventilated spaces, such as those listed below in a) to e), shall be provided
directly or by transfer of less vitiated air from an adjacent space, and shall be sufficient to permit the
exhaust airflow requirements of 6.4 to be met:
a) public sanitary rooms (bath, shower, urinal or W.C.);
b) laundry;
c) drying-and ironing-rooms;
d) changing-rooms;
e) cleaning-lockers.
NOTE It is assumed that supplementary means of heating are provided for ventilated spaces where
necessary.
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ISO 7547:2022(E)
6.3 Temperature of supply airflow
The temperature of the cooling air supplied to the space shall not be more than 15 °C lower than the
average temperature nor, for the heating mode, more than 22 °C higher than the average temperature
of the space.
6.4 Exhaust airflow
6.4.1 Volume of airflow
The exhaust airflow in saloons, mess- and dining-rooms and common day-rooms shall be the same as
the supply airflow.
The exhaust airflow in hospitals, pantries and smoking rooms (if installed) shall be at least 20 % more
than the supply airflow.
3
The exhaust airflow in private sanitary rooms (bath, shower or W.C.) shall be 0,02 m /s or a minimum
of 10 air changes per hour, whichever gives the highest value.
The exhaust airflow in common sanitary rooms (baths, shower, urinal or W.C.), laundries and drying-
and ironing-rooms shall be a minimum of 15 air changes per hour and in changing-rooms, washrooms
and cleaning-lockers a minimum of 10 air changes per hour.
Public sanitary rooms in passenger ships, including ferries, shall be given special consideration. The
3
exhaust airflow shall be a minimum of 15 air changes per hour or the volume calculated from 0,04 m /s,
whichever gives the highest volume.
6.4.2 Exhaust system
The exhaust system from the spaces listed below in a) through d) shall be fed directly to the open air,
and not used for recirculation. Additionally, the exhaust systems for each of these spaces or group of
sp
...